Abstract: A fluorescence resonance energy transfer (FRET) mechanism based on squaramide probe SA was proposed for the selective detection of nitro aromatic explosives. In DMSO buffered solution, the meisenheimer complex formed between explosives and probe SA could effectively quench the emission of SA along with the significant absorption intensity enhancement and distinct solution color change. As a result, SA was capable of recognizing TNT qualitatively and quantitatively by using UV-Vis and photoluminescence spectroscopes, as well as distingui-shing NT、DNT、TNP qualitatively and quantitatively by using photoluminescence spectroscopes.